Hydraulic machine



1386- 1, 1953 F. J. KENT ET AL 2,660,955

HYDRAULIC MACHINE Filed June 27, 1950 5 Sheets-Sheet l T)ME DELAY I I INVEN TOR.S FRRNC/J \J. KEN 7- Dec. 1, 1953 Filed June 27, 1950 F. J. KENTET AL 2,660,955

HYDRAULIC MACHINE 3 Sheets-Sheet 2 Dec. 1, 1953 Filed June 27, 1950 F.J. KENT ET AL HYDRAULIC MACHINE 5 Sheets-Sheet 5 Patented Dec. 1, 1953HYDRAULIC MACHINE Francis J. Kent and Reymond M. Reichl, Forest Hills,N. Y York, N. Y

Application June 27,

This invention relates to fluid pressure operated machines andespecially to pressure changing mechanism suitable for use therein suchas in hydraulic testing machines for tubes, pipes, or the like.

Hydraulic mechanism for increasing pressure is known, such usuallycomprising a large cylinder with a ram or piston and a small cylinderwith a ram or piston, the pistons being coupled to each other. In suchan instance, when low pressure fluid is delivered to the large cylinder,the pistons will move together and fluid of higher pressure will bedeveloped from the-high pressure cylinder.

cuits can be arranged so as to automatically provide the desired cycleof movement of the intensifiers.

In another aspect of the invention, two pumps can be employed forsupplying the low pressure fluid to the intensifiers. large main pumpand'the other a smaller auxiliary One of these may be a assignors toHydropress, Inc., New a corporation of Delaware 1950, Serial No. 170,6248 Claims. (61. 103-45) where the low pressure side is driven by oil andthe high pressure side involves water.

These and other advantages, objects and features of the invention willbecome apparent from the following description and drawings.

In the drawings:

Figure 1 illustrates schematically one form of Figure 3 is similar toFigure 2 with the exception that the right hand piston has moved fur-Figure i is generally similarto the preceding figures with the exceptionthat one of the valves has moved so that the right hand piston can movedownwardly while the left hand piston is on its power stroke.

Figure 5 is an enlarged view, partially in sec,- tion, showing one formof a twin cylinder intensifier.

Figure 6 is a fragmentary top view of Figure 5.

Referring first to Figure 1, the twin intensifier arrangement it has aright hand unit HA and a left hand unit iiB. Rams IZA, i213 have highpressure portions 83A, sure portions iA and MB. Said rams operate inhigh pressure cylinders 55A, 15B and low pressure cylinders 16A, HEB,respectively.

n The highpressure cylinders have outlets 17A,, ilB leading to the highpressure connection 33 through suitable check valves 20, 20. Water canbe supplied to the system through the suction check valves l9, l3. Limitswitches 21A, 2|B, 23A, and 23B are placed along the cylinder and areoperative according to the position of the rams. These switches areconnected through schematically illustrated wires 24,, 25 with themaster controller 2%, said master con-- troller in turn being connectedto the solenoids of the various control valves as will be explainedhereafter. The master controller can have a suitable start push buttonassociated therewith.

The motivating pressure source for the intensifier can comprise pumpunit 21. employing a main pump 23 and an auxiliary pump 2.9, said pumps.being driven by a suitable electric motor 3 The main oil pump 28preferably is" of the variable delivery type and the pressure therefromis used for the main compression or upward movement of both of theintensifier units. This pump may be provided with an automatic controlso that delivery volume is reduced when a predetermined outlet pressureis reached;

The auxiliary pump can be smaller than the main pump and used for theprecompression movement in each of the intensifiers as well as for thereturn movement of the rams. This pump may be of the constant deliverytype but preferably is of the variable delivery type similar to the mainoil pump. The main oil pump is connected by means of pipe 31 to the mainfour- The auxiliary pump 29 is connected by pipe 33 with the mainfour-way control valve 32, which control valve may take various forms.In the form schematically shown, it is operated by means of solenoid 34which positions the valve stem 35 as desired in valve body 36, thesolenoid being controlled by the master controller 26. The secondaryfour-way control valve 31A controls the flow of fluid to and from theright hand intensifier unit I IA, and the second secondary fourwaycontrol valve 313 controls the flow of fluid to and from the left handintensifier unit HB. Secondary control valves 31A and 3113 havesolenoids 38A and 383 connected with the master controller 28 in such amanner as to position valve stems 39A and 393 as called for by thecontrol circuits.

The pumps are suitably connected with the oil storage tank 40, saidstorage tank having pipe 4! connected thereto for receiving liquid fromthe return ports of the secondary four-way valves.

The main control valve 32. serves as the switchover valve for changingmain operating pressure from one intensifier unit to the other. Thesecondary control valves 31A and 31B serve to control the reversal offlow of oil so as to effect return of the rams and also have by-passpositions.

At the start of a cycle, both intensifiers will be in the position shownin Figure 1. At that time, the valve stem of main control valve 32 willbe in position to connect the motivating fluid pressure means or to feedmain high pressure oil through pipe 42 to control valve 31A, which inturn through pipe 43 is connected to low pressure cylinder USA. Thiswill serve to start the movement of the intensifier ram upwardly andthus cause high pressure to be furnished at'the outlet of the highpressure cylinder 115A. The opposite or upper side of low pressurecylinder WA is connected through return pipe 44A, port 45A, port 46A andreturn line 4|, to storage tank 40.

At their lowermost position, both rams will engage their lowermost limitswitch MA, 2135, respectively.

With the main control valve in the position shown in Figure l, auxiliarypump 23 will be connected through line 33, port 41 in control valve 32,and port 46 to the secondary control valve 313, controlvalve 313 beingillustrated in the bypass position in Figure 1. When ram l'ZA dur ingits upward movement engages limit switch 22A (Figure 2), secondary valve313 will be moved to. the left by solenoid 3815 so as to connectauxiliary pump 29 through port 493, port 303,, line 5lB with the lowerside of cylinder |6B,, thus subjecting the idle intensifier cylinder MBto the auxiliary pump pressure or a precompression pressure. The fiuidin the high pressure cylinder in said left unit will be pre compresseduntil the pressure is equal to that in the operating or rightintensifier unit. For a certain interval of time, the two intensifierunits may be moving upwardly together, but no increase in pressure willoccur because the automatic pressure control of one or both of the pumpswill reduce the delivery in accordance with the pressure.

As soon as ram i2A reaches its upper position (Figure 3') wherein itcontacts the upper limit switch 23A, such will serve to move the maincontrol valve 32 to the right (Figure 3) which will disconnect the mainpump 28 from the secondary control valve B'lA and will connect the mainpump through valve 32, port 46, pipe 52, port 49B, port 5013, line 558to the lower side of the left hand low pressure cylinder 1GB. Pipe 44Bof the left unit will be connected through secondary control valve 31Bwith return line to the tank 4%.

The aforementioned movement of main control valve 32 (Figure 3) causesauxiliary pump 29 to be connected to secondary control valve 31A throughline 42. After a short predetermined delay, by means of a suitable timerelay valve, shown diagrammatically connected to control box 26, valve31A will be moved to the right (Figure 4) so as to connect the auxiliarypump 29 through line 42, port 45A, line MA with the top of the righthand low pressure cylinder USA, and thus will cause movement of theright hand pressure intensifier cylinder downwardly.

When the right hand ram l2A again has reached its lower position, thelower limit switch 2 IA will be operated and place the control valve 31Ain a bypass position similar to the position of valve 313 in Figure 1.At this time, one half of the cycle will have been completed.

As the left ram I2B moves upwardly, it will contact the various limitswitches 22B, 2313 in a manner similar to that described for the righthand intensifier unit, so that the right hand intensifier will haveprecompression fluid intro duced in the low pressure cylinder ram andthe cycle repeated.

As an example of one specific form which the twin intensifier unit cantake, reference may be made to Figures 5 and 6 wherein base i5 hasmounted thereon low pressure cylinders 15, said cylinders being fastenedto the frame by bolts 11. Intermediate frame 13 connects high pressurecylinders 19 to the base 15. The high pressure cylinders may have outletapertures 39 in the top and the low pressure cylinders may have mainpressure inlets 8| near the bottom thereof with return pressure openings82 adjacent the top thereof. The low pressure ram 83 is connectedto'high pressure ram 84 in any suitable manner.

main control valve 32serves toselectively precompres'sion at the correctside of said cylinders with motivating pressure fluid means, flowcontrol means controlling the flow of motivating fluid to saidcylinders, piston stroke controlled means connected with said flowcontrol means for the'motivating pressure cylinders to alternatelyenergize the same, and control means connecting one of said cylinderswith a precoinpression source of fluid While the other piston is movingin its pressure stroke and before it has completed its stroke and hasbeen reversed, so that a substantially constant pressure will bedelivered by said intensifiers.

2. In a pressure changing fluid motor apparatus, the combinationcomprising at least a pair of cylinders having pressure stroke ends andreturn stroke ends, a reciprocable piston in each of said cylinders, asource of motivating pressure fluid, a main switch-over control valveconnected with said motivating pressure fluid means, a secondary controlvalve for each of said cylinders, said secondary control valves beingconnected to said main control valve and to the pressure stroke ends'oftheir respective cylinders, control means connected with said secondarycontrol valves operated in response to movement of the first of saidpistons on its pressure stroke to move one of said secondary valves toadmit precompression fluid pressure to the other of said cylinders Whilethe first piston is still on its pressure stroke, and control meansconnected with said switch-over valve for changing said motivatingpressure fluid from one cylinder to the other.

3. In a fluid motor apparatus connected with a fluid pressure changinghydraulic means, the combination comprising at least a pair of pressurechanging cylinders having pressure stroke ends and return stroke ends, areciprocable piston in each of said cylinders, a source of motivatingpressure for said cylinders, a pair of valves controlling the inlet andoutlet of fluid from the pressure stroke ends of said cylinder means,and control means connected to said valves responsive to movement ofsaid pistons at a point intermediate the ends of the strokes thereof foradmitting a first precompression pressure to one of said cylinders Whilethe piston in the other is on its pressure stroke and before motivatingpressure is admitted thereto.

4. In a pressure changing fluid motor apparatus, the combinationcomprising at least a pair of fluid motor cylinders having pressurestroke ends and return stroke ends, a reciprocable piston in each ofsaid cylinders, a main motivating pressure fluid means, an auxiliarypressure fluid means, control valve means connected with said 5. In apressure changing fluid motor apparatus, the combination comprising atleast a pair of fluid motor cylindershaving pressure stroke ends andreturn stroke ends, each of said cylinders having a reciprocable pistontherein, main main motivating pressure fluid means and said auxiliaryfluid means alternately With said cylinin the other cylinder has reachedthe end of its pressure stroke under the influence of the mainmotivating pressure fluid, and stroke controlled means connected to saidsecondary valve means connecting said auxiliary pressure 6. In a fluidmotor apparatus, the combination comprising a pair of cylinders havingpressure stroke and return stroke ends,

fluid source, secondary valve means for each pressure stroke end andconnected therewith controlling flow of pressure fluid to and therefrom,a main switch-over valve connected to said main and auxiliary fluidpressure alternately to one of said power stroke ends before the otherpiston has completed its pressure stroke under influence of the ma nmotivating pressure fluid. 7. In a pressure changing fluid motorapparatus, the combination comprising a pair of cylin- '3 controllingthe flow of main and auxiliary pres-1 sure iiuid to each or saidsecondary valve means, valve operators connected to said main valve andsecondary valves, piston stroke controlled limit switch means in thepath of operation of each of said pistons selectively operating saidvalve operators for each of said valves, said switch means including afirst switch for each piston connected with the main valve operator toalternate the main fluid source between said pistons, a second swch -foreach piston connected to its seconda v valve means alternatelyconnecting a ton th said auxiliary fluid source heiore the other pistonhas reached the end of its pressure stroke, so that the source ofauxiliary pressure connected to one of said pressure stroke ends ceiorethe other piston has completed its pressure stroke under influence orthe main motivating pressure fluid, and means shifting auxiliarypressure to the return stroke end after the piston reaches the of itsstroke.

8. In a pressure changing fluid motor apparatus, the combinationcomprising a pair or cylinders hav a pressure stroke and return strokeends, a reciproca'tcle piston in each or said cylinders, a mainmotivating pressure fluid source, an auxiliary pressure fluid source,secondary valve means for each pressure stroke end controlling flow ofpressure fluid to and therefrom, a main switch-over valve connected tosaid fluid sources controlling the flow or" main and auxiliary pres--sure fluid to each or said secondary valve means, valve operatorsconnected to said main valve and secondary valves, piston strokecontrolled limit switch means in the path of operation of each of saidpistons selectively operating said valve operators for each of saidvalves, said switch means including a first switch for each pistonconnected with the main valve operator to alternate the main fluidsource between said pistons, a second switch for each piston connectedto its respective secondary valve means alternately connecting a pistonWith. said auxiliary fluid source before the other piston has reachedthe end or its pressure stroke, so that the source of auxiliary pressureis connected to one of said inlet pressure stroke ends before the otherpiston has completed its pressure stroke under influence of the mainmotivating pressure fluid, time delay means connected with saidsecondary valve operators shifting the auxiliary pressure to the returnstroke end of a cylinder after the piston therein. reaches the end ofits pressure stroke.

FRANCIS J. KENT. REYIVIO'ND M. REICHL.

References Gited in the file of this patent UNITED STATES PATENTS

